IPAddr を使う。
require 'ipaddr' ip = IPAddr.new('192.168.0.1/24') puts ip.to_range.to_a.first(5) puts ip.to_range.to_a.last(5)
192.168.0.0 192.168.0.1 192.168.0.2 192.168.0.3 192.168.0.4 192.168.0.251 192.168.0.252 192.168.0.253 192.168.0.254 192.168.0.255
